Kiln retort structure



J y 7, 9 R. s. KENT 2,046,687

KILN RETORT STRUCTURE Filed Nov. 9, 1954 2 Sheets-Sheet 1 1 :wwzm [5 Inl l ll 3f 1 as H y 1 i Z e l l 1 1 r Eli A9 1 k a L /7 I K37 /0 it L a 11 3 v 2; 7 z I INVENTOR July 7, 1936. s T 2,046,687

KILN RETORT STRUCTURE Filed Nov. 9, 1934 2 Sheets- Sheet 2 '46 27INVENTOR ATTORNEY Patented July 7, 1936 UNETED STATES ATENT OFFICE} 3Claims.

This invention relates to improvements in kilns for drying pulverulentmaterial and especially for drying and revivifying char for use infiltering processes in connection with sugar refining; and. theinvention has reference, more particularly, to a novel retort structurefor such kilns.

This invention has for its principal object to provide a novelself-ventilating retort structure for char kilnswhichoperateswithhigherefficiency and more rapidly at the temperaturesordinarily heretofore employed (approximately 1000 degrees F.), or withequal efficiency but less rapidly at lower temperatures than heretoforecustomarily used, by virtue of the fact that the vapors and products ofdistillation are quickly vented, while in a highly heated state,directly from the retort interiors into the combustion chamber of thekiln without opportunity to contact with the incoming cold stream ofchar.

The invention has for a further object toprovide a novelself-ventilating retort structure of multiple pipe form whereby a largeincrease of heating surface area contactable by the char is provided ascompared with the available area of the old cast iron single piperetorts, while nevertheless occupying no more space than required forsaid old single pipe retorts, novel vent means being provided inconnection with each individual pipe.

Another object of this invention is to provide a multiple pipe retortwherein the pipes are preferably of drawn chrome-steel alloy, thusgreatly reducing the weight of the retort while at the same timeincreasing the heat transfer efficiency thereof, in combination withnovel means for mounting the multiple retort pipes subject to easy andcomparatively quick removal for the purpose of adjusting the same in thekiln to correct warpage, or for replacement when the useful life of thesame is ended; the mounting arrangement including novel means wherebyeach retort pipe is self-ventilating.

Other objects of this invention, not at this time more particularlyenumerated, will be understood from the following detailed descriptionof the same.

Illustrative embodiments of the invention are shown in the accompanyingdrawings, in which:-

Fig. 1 is in part a front elevation and inpart a vertical cross sectionof a kiln equipped with the novel retort structure according to thisinvention, one of the multiple pipe retorts being shown in elevation andone in vertical section; Fig. 2 is a detail horizontal section, on anenlarged scale, taken on line 2-2 in Fig. 1; Fig. 3 is another detailhorizontal section, also on an enlarged scale, taken on line 3-3 in Fig.1.

Fig. 4 is an enlarged View similar to that of Fig. 1 but showing themethod of handling the retort structures for shifting or replacement.

Fig. 5 is an enlarged elevational view of the top header of the novelmultiple pipe retort; and Fig. 6 is an enlarged elevational view of thebottom header of the same.

Fig. 7 is a fragmentary view in part elevation and in part section of asomewhat modified form of the multiple pipe retort structure; and Fig. 8is a horizontal section, taken on line 8-8 in said Fig. 7.

Similar characters of reference are employed in the above describedviews, to indicate corresponding parts.

Referring to the drawings, the reference character l indicates the kilnwhich is usually constructed of brick. Located within the upper centralportion of the kiln is a combustion chamber 2 enclosed by the side walls3, top arch 4 and floor wall 5. Located beneath the floor wall 5 are airboxes 6 which communicate with the com bustion chamber through saidfloor wall 5, so that adequate air to support the combustion of fuelwithin said combustion chamber is delivered to the latter. Locatedwithin the kiln between the outer walls thereof and said combustionchamber side Walls 3 are vertical retort chamhers I, through which theburning gases issuing from the combustion chamber 2 are caused to pass,thus constituting the same continuations of the combustion chamber 2.

Mounted in the fiooor 8 of the kiln, so as to be rigidly and firmlysupported thereby within the lower ends of the retort chambers 1, areretort footing members 9 having upstanding peripheral walls It] boundingseating cavities or sockets H. Projecting from the underside of eachfooting member 9 are a plurality of laterally spaced tubular dischargespouts l2, the passages l3 of which communicate Wtih the interior of theseating cavity or socket ll. Connected with and extending downwardlyfrom said spouts l2 are cooler pipes 42 into and through which thematerial treated in the retorts is discharged.

The upper end of the retort chamber 7 is providedwith a suitablysupported cover plate l4 having dependent passage or hatchway formingmembers I5 for communication with the retort members per se. Arrangedabove each series or gang of retort members, which extend through theretort chambers I as will subsequently appear,

are feed hoppers l6 leading from the bin l1 into which the material tobe treated in the retorts is supplied, so as to flow therefrom bygravity downwardly through the retort members.

The retort members are arranged in gangs extending downwardly andvertically through the retort chambers I of the kiln. According to thepresent invention the said retort members involve a novel form andconstruction to be now set forth, a detail description of one of whichwill sufiice for all. Each retort comprises a set of pipes I8 of drawnsteel or other suitable metal or material, preferably three in number,arranged side by side in laterally spaced apart relation to extendvertically through a retort chamber 1 when in place. The pipes l8 makingup a retort forming set thereof are maintained in their grouped relationat their lower ends by means of a bottom header Hi. This bottom headeris provided in its upper portion with spaced sockets 25 to receive thelower ends of said retort pipes I8. Opening through the bottom wall 2|of the header i9 are discharge openings 22 axially aligned with thebores of said retort pipes 18, said openings 22 being of less diameterthan the diameter of the pipe receiving sockets 20, thereby providingannular supporting shoulders 23 upon which the lower ends of said pipes18 are engaged. On its under side, said bottom header i9 is providedwith a plurality of spacer lugs 24 dependent therefrom and preferablyarranged in radial relation to the vertical axes of the sockets 29 andthe openings 22 so as to form outwardly extending lateral vent channelsor spaces 25 between the bottom of the header l9 and the floor of theseating cavity or socket ll of the footing member 9. The externaldimensions of the bottom header 1!) are somewhat less than the internaldimensions of the walls ID of the footing member 9 which bound theseating cavity or socket ii of the latter, thus providing an upwardlyextending vertical vent space 26 providing communication between theaforesaid lateral vent channels or spaces 25 and the interior of theretort chamber 1 in which the retort member is located.

In installations wherein it is not desired to provide theabove-described means providing for ventilation communicating with thelower ends of said retort pipes l8, the bottom header I9 may be suitablysealed into the footing members 9, or any other means may be providedfor sealing the lower ends of the retort pipes against communicationwith the interior of the retort chamber I of the kiln.

The pipes l8 making up a retort forming set thereof are maintained intheir grouped relation at their upper ends by means of a top header 21.In one form thereof this top header is provided with a bottom wall 28from which depend tubular necks 29, the passages of which communicatewith the interior passage 38 of said top header. The external diametersof said necks 29 are somewhat smaller than the internal diameters of thebores of said retort pipes l8, so that said necks enter the upper endsof the latter when the top header is operatively assembled therewith,thereby forming a loose connection providing vertical vent spaces 3|. Onits underside, said top header is provided with a plurality of spacerlugs 32 dependent therefrom and arranged in radial relation to andextension from said necks 29 so as to form outwardly extending lateralvent channels or spaces 33 therebetween. The upper ends of the retortpipes l8 abut said spacer lugs 32, and consequently the vent spaces 3|leading from said pipe interiors communicate with said lateral ventchannels or spaces 33 and through these with the interior of the retortchamber '1. At its upper end portion, the top header is provided with alaterally enlarged coupling portion 34 to receive the hatchway formingmembers i5 of the retort chamber cover plate hi. Intermediate its ends,said top header is provided with an external laterally extending flangeor shoulder 35 which is disposed, when the top headers of the retortsare in place, in the plane of shoulders 38 with which the side walls ofthe retort chamber l is provided. Said shoulders 35-36 serve assupporting means for sealing plugs 3'! of fire clay or brick, wherebythe upper ends of the retorts are sealed within the retort chamber 1.

The arrangement for mounting the multiple pipe retort, as thus abovedescribed, is such that the entire structure including the top header 2?is supported by the footing of the bottom header l9 in the footingmembers 9. This arrangement is satisfactory as a whole, but in somecases it is desirable to so mount the retort that the top header 2'5 issupported independently of the retort pipes [8, whereby play may beallowed between the top header 2'! and the upper ends of said retortpipes so that the latter are free for movement under longitudinalstresses due to expansion and contraction thereof. A mountingarrangement suitable for obtaining the latter results is shown in Fig. 7wherein a carrying plate 43 is bridged across the upper end of theretort chamber 1, being supported on the wall shoulders 36. Thiscarrying plate 43 is provided with openings 44 through which the lowerend of the top header 2'! is passed, and the top header is provided withan external annular hanger flange 45 to engage the carrying plate 43,whereby the top header is independently supported. With the top header2'! thus independently hung or supported, the upper ends of the retortpipes [8 may be so engaged on the necks 29 so as to be capable ofsliding play thereon, which play will permit free movement of the pipesunder stresses of longitudinal expansion and contraction thereof.

In Figs. '7 and 8 there is also shown a modified form of retort pipeengaging neck 29, the modification consisting in providing the same withcircumferentially spaced externally projecting vertical ribs 46, which,when the ends of the retort pipes I8 are engaged over the necks 29,function to space the pipe walls outwardly from the neck walls, therebymaintaining the vertical vent spaces 3| uniformly concentric to thenecks 29.

When the retort members are in place within the kiln as above described,the products or gases of combustion generated within the combustionchamber 2 pass into the upper ends of the retort chamber 7 throughentrance ports 38 provided in the side walls 3 of said combustionchamber. The hot gases thus delivered into the retort chamber 1circulate around the pipes I8 of the retort members, and thence flowdownwardly for escape through discharge ports 39 leading to the furnacefiues 49, and thence to the stack conduit 4|, all as indicated by thedirection arrows applied in Fig. 1 of the drawings.

Char or bone-black, or other material to be treated, is supplied to thebin II, from whence it flows by gravity through the feed hoppers l6 andhatchway forming members l downwardly through the top header 21 into andthrough the retort pipes l8 for final discharge from the latter, aftertreatment, through the cooler pipes 42.

Inasmuch as the retort members each comprise a group of spaced drawnsteel pipes I8, as compared with the common single cast iron piperetort, a much higher heat transfer eificiency is obtained; first, byreason of a greater area of pipe surface externally exposed to contactby the hot gases of combustion circulated through the retort chambers land around the retort members as well as a greater area of pipe surfaceinternally exposed to contact by the char gravitating through the retortpipes, and, second, by reason of the higher conductivity of therelatively thin walls of such steel retort pipes. In the preferred formof three pipe retort member, as herein shown and described, theeffective surface area of the retort members is increased from one-thirdto one-half more than that furnished by the old single pipe retorts. Asa result of this the kilns may be satisfactorily operated at the samerate of material flow as employed in the old single pipe retorts, but ata lower temperature than required for the latter, or, conversely, thesame temperatures heretofore used with the single pipe retorts may beemployed, but with an increased rate of material flow through the retortmembers. Another advantage of the multiple pipe retort according to thisinvention lies in the fact that the retort members are of considerablyless weight, and consequently can be handled with less labor anddifficulty when replacements, repairs or adjustments are required.

While the above mentioned advantages involved in the use of thin walledmultiple pipe retorts are desirable, such advantages are somewhatoff-set if not altogether lost in the absence of satisfactory means forventilating the individual pipes. So far as I am aware no satisfactorymeans for such purpose has heretofore been available, and consequentlyit is an important object of this invention to provide a constructionwhereby ventilation of the individual retort pipes may be attained tothe end that the products of distillation generated by the treatment ofmaterial, such e. g. as char, may be quickly and efliciently removed,while in a highly heated state, from the interior of the retort pipesand away from possible contact with the incoming char stream; for ifpassed up through the comparatively cold stream of incoming char, thevapors constituting these distillation products are likely to becondensed and absorbed by the incoming char, thereby increasing the loadof impurities carried by the latter and consequently rendering theeificient revivification of the char more difficult.

By reason of the construction and arrangement of the novel header meansprovided by this invention for maintaining the retort pipe sets inoperative grouped arrangement, the desired functional advantages areprovided whereby each retort pipe is rendered self-ventilating. When,under the application of heat to the char or other material treated inthe retort pipes, the liberated vapors and gases constituting theproducts of distillation are released, the same are easily and quicklydriven off without impeding the flow of the material. This is due to theprovision of the venting spaces and channels formed between the ends ofthe retort pipes and either one or both of the header members as abovedescribed. The liberated vapors and gases readily escape from both endsof the retort pipes through these venting spaces'and channels into theretort chambers l to be carried off by the kiln draft circulation; thenovel arrangement being such that the venting is effectively establishedwithout sacrifice of the secure maintenance and holding of the retortpipes in their desired spaced and grouped relation.

Another advantage of the novel multiple pipe retort structure lies inthe ease with which the same may be handled for replacement, adjustmentor repair. For example, in the operation ofthe kiln, the steady flow ofheat against the external surfaces of the retort pipes, tends in time tosomewhat Warp the same, ordinarily in the direction toward the incomingheat. In such case, it is a comparatively easy matter to open up the topof the kiln and by meansof a line or grapple (as shown in Fig. 4) toengage the bottom header and thereupon lift out the retort member, sothat the same may be turned and replaced in such position thatapplication of incoming heat will tend to reversely warp the pipes l8back to initial condition. Owing to the fact that the connectionsbetween the retort pipes and the headers form relatively loose joints,it will be obvious that, when the retort is lifted out of the retortchamber 1, the pipes may be easily and quickly either individuallyturned relative to or entirely dismounted from the headers and replacedby new pipes when such replacement is desirable.

I am aware that various changes may be made in the construction of theretort members as above described and as illustrated in the drawings,without departing from the scope of and while still retaining thegeneral principles of this invention. Hence, I do not limit my inventionto the exact arrangements and combinations of the devices and parts asdescribed in the foregoing specification, nor do I confine myself to theexact details of the construction of the various parts as illustrated inthe accompanying drawings.

I claim:

1. A retort member for kilns having a highly heated retort chamber,comprising a plurality of pipes disposed in parallel verticallyextending and laterally spaced relation within said retort chamber, abottom header to engage and hold the lower ends of said pipes, saidbottom header having discharge openings with which the pipescommunicate, and a top header having an upwardly open main passage and alower end Wall, tubular necks depending from said lower end wall andcommunicating With the main passage of said top header, said necksengaging loosely in the upper ends of said pipes, and spacer lugsprojecting from the underside of said lower end wall radial to saidnecks to space the pipe ends from said end wall thereby providing ventspaces opening directly into the heated interior of said retort chamberin communication with the interiors of said pipes.

2. In a kiln of the class described having a combustion chamber, retortmeans comprising a plurality of vertically disposed laterally spacedpipes extending in grouped relation through the combustion chamberbetween the top and bottom thereof, a bottom header for each pipe groupfooted in the bottom of said combustion chamber to which the lower endsof said pipes are engaged, a top header for each pipe group sealed inthe top of said combustion chamber, each top header having means,providing a char receiving passage externally of said combustion chamberand a lower end wall therefor, tubular necks depending from said lowerend Wall and communicating with said char receiving passage, said necksloosely engaging in the upper ends of said pipes, and means to spacesaid pipe ends relative to said end wall and necks to form escapepassages for vapors and products of distillation leading from the pipeinteriors directly into the combustion chamber.

3. In a kiln of the class described having a combustion chamber, retortmeans comprising a plurality of vertically disposed laterally spacedpipes extending in grouped relation through the combustion chamberbetween the top and bottom thereof, a top header for each pipe groupsealed in the top of said combustion chamber, each top header havingmeans providing a char receiving passage externally of said combustionchamber and a lower end wall therefor, tubular necks depending from saidlower end wall and communieating with said char receiving passage, saidnecks loosely engaging in the upper ends of said pipes, means to spacesaid pipe ends relative to said end wall and necks to form escapepassages for vapors and products of distillation leading from the pipeinteriors directly into the combustion chamber, a bottom header for eachpipe group having sockets to receive the lower ends of said pipes anddischarge openings leading from the bottoms of said sockets, a footingmember for each bottom header fixed in the bottom of said combustionchamber, and means to space the bottom header relative to the footingmember to form additional escape passages for vapors and products ofdistillation also leading from the pipe interiors directly into thecombustion chamber.

ROBERT SAYRE KENT.

